Magnetic-disk drives generally utilize rotary actuators to position one or more magnetic read/write heads (also known as transducers) with respect to a similar number of magnetic disks rotatably mounted on a hub driven by a motor. The read/write heads are moved among particular tracks of the magnetic disks to gain access to the information recorded on those track and/or to write information to a particular location on a disk.
The read/write heads for a particular disk are mounted on an air bearing slider. The slider positions the read/write heads above the data surface of the corresponding disk by a cushion of air generated by the rotating disk. Alternatively, the slider may operate in contact with the surface of the disk. The slider is mounted to a suspension load beam or suspension arm. The suspension arm maintains the read/write heads and the slider adjacent to or in contact with the data surface of the corresponding disk with as low a loading force as possible. The combination of the read/write heads, slider and suspension arm is sometimes referred to as the head gimbal assembly (HGA).
The suspension arm is connected to the distal end of a rotary actuator arm pivotally installed within the housing of the disk drive. A voice coil motor pivots the actuator arm to position the read/write heads over desired tracks at selected radii of the magnetic disk.
Rotation of a disk at very high RPMs within the disk drive creates an air flow pattern within the disk drive and creates the cushion of air mentioned above. A particular air flow pattern created depends upon a number of factors to include the number of disks used in the particular drive, the RPM speed of the rotating disk(s), as well as the particular shape of the interior surfaces of the disk drive. However, air flow in the drive also exerts a force on the suspension arm and actuator arm that destabilizes tracking of the transducer.
Disk drive capacity has been increased by incorporating higher disk track densities. In order to accommodate these higher disk densities, the heads must be made smaller and are required to fly closer to the disk in order to be capable of reliably reading and writing data to and from the disk surface. As the disk is rotating, each head is supposed to follow a certain track on the disk surface. The tracks typically contain servo information used in a servo routine to locate and maintain a center position for the heads. Many factors can cause a particular head to be misaligned with respect to a track. Some of these factors include disk warpage, disk vibration, windage, motor run out and others. Some servo systems may have the capability to correct these adverse influences to a certain degree. However, there is always a small amount of inaccuracy present in a head following the center of a disk track. This inaccuracy can be referred to as track misregistration.
One example of a prior art device used to reduce the adverse effects of air flow on an actuator arm is disclosed in U.S. Pat. No. 6,762,908. The disk drive disclosed in this reference includes an air deflector or disk stator which deflects at least a portion of air flow away from the actuator arm assembly of the drive. The air deflector is in the form of a c-shaped finger that attaches to the magnet post of the voice coil motor.
Although disk air deflectors or disk stators can be useful in remediating undesirable effects of air flow on an actuator arm, as well as to reduce overall disk vibration and windage, disk stators add significant cost to a disk drive. Many disk stators have complex shapes, and the cost to machine each disk stator, in conjunction with the cost of the materials, can inhibit the commercial viability of the disk drive. Thus, there is a need for a cost effective yet functional disk stator.
Additionally, for disk packs, it is necessary to mount multiple disk stators so that they extend between the gaps of the stacked disks, but do not contact the disks. Current disk drives have very small gaps between the disks in a disk pack, therefore, the stators have to be precisely positioned so that they do no inadvertently contact the disks. During a shock event, if a stator contacts the media of a disk, such contact can ruin the disk making the disk drive inoperable. Therefore, there is also a need for providing a cost-effective disk stator design that contributes to exact placement of a group of stators in a disk pack to prevent contact with the surfaces of the adjacent disks.